list_ligands

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the burden for behavioral disclosure. 'Lists' clearly signals a read-only operation, and the qualifier 'small-molecule (organic)' adds a meaningful constraint (excluding metals/ions). It doesn't describe return format or side effects, but the output schema covers return values, making this adequate for a simple list tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact and front-loaded: the first sentence states the purpose, the second gives usage guidance. Every sentence earns its place with no filler or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple list tool, the description covers purpose, usage context, and parameter semantics. The output schema exists to document return values, so the description doesn't need to explain them. It doesn't address edge cases like an object with no ligands, but those are not critical for this tool's basic operation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and the parameter obj_name is already clearly described as 'Object to inspect for organic ligands.' The tool description adds no additional parameter-specific meaning, so it sits at the baseline score for high coverage.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb 'Lists' and targets a clear resource: 'small-molecule (organic) ligand residue names in an object.' It explicitly differentiates from sibling listing tools like list_objects and list_chains by focusing on ligands, and it even names the downstream view functions it supports.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It provides explicit when-to-use guidance: 'Call this before ligand_view, pocket_view, or pharmacophore_view when you don't already know the ligand's 3-letter residue name.' This gives a clear usage context, though it doesn't discuss when not to use it or mention alternatives, so it doesn't earn a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.